Snubber circuits have many applications in power electronics circuits such as voltage and or current rise limiters, level clamps, EMI limiters, and damping networks. Prior art snubber circuits, to be discussed hereinbelow, control the snubbing action under one set of circuit conditions, i.e. during switch on or switch off time. Snubbing is accomplished by selectively storing energy in a capacitor during one portion of an operating cycle and discharging the energy during a second portion of the cycle.
Using such a snubber with integrated power supply control circuits may pose a problem, in that the control circuit may shut down while trying to absorb the energy stored in the capacitor. Reducing the size of the snubber capacitor of course solves this problem but may well result in a capacitor incapable of controlling the ringing.
A general object of the present invention is to provide a snubber circuit which can provide two levels of current flow respectively well suited to control ringing and turn on.